Here's a way to crack the zip files with passwords. First of all download and install fcrackzip, if you're on a debian based distro the command to run is :

# aptitude install fcrackzip

That's all. Once it's installed you'll have to run the command with few parameters here's some explanation of some options :

-b option will let you select the brute force attack mode. This means that it'll trie all the possibilities.